U.S. patent application number 12/224227 was filed with the patent office on 2009-05-21 for antistatic hard coat film.
Invention is credited to Yoshihisa Kimura, Keiichi Kitahara, Masuo Koyama, Kazushige Matsumoto, Hikaru Nishinaga, Masato Saito.
Application Number | 20090130464 12/224227 |
Document ID | / |
Family ID | 38509232 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090130464 |
Kind Code |
A1 |
Nishinaga; Hikaru ; et
al. |
May 21, 2009 |
Antistatic Hard Coat Film
Abstract
An antistatic hard coat film showing antistatic property and
antireflection property for outer lights as well as superior hard
coat properties such as superior surface hardness and
antiscratching property is provided. The antistatic hard coat film
of the present invention comprises an antistatic hard coat layer
formed from an ionizing radiation curable resin, a pigment and a
polymer antistatic agent having an organopolysiloxane unit and a
quaternary ammonium salt unit, and the hard coat layer contains 1
to 5% by weight of the pigment. Weight ratio of the ionizing
radiation curable resin and the polymer antistatic agent is
preferably 6:4 to 5:5.
Inventors: |
Nishinaga; Hikaru; (Saitama,
JP) ; Kitahara; Keiichi; (Saitama, JP) ;
Saito; Masato; (Saitama, JP) ; Matsumoto;
Kazushige; (Saitama, JP) ; Koyama; Masuo;
(Saitama, JP) ; Kimura; Yoshihisa; (Tokyo,
JP) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE, FOURTH FLOOR
ALEXANDRIA
VA
22314-1176
US
|
Family ID: |
38509232 |
Appl. No.: |
12/224227 |
Filed: |
February 13, 2007 |
PCT Filed: |
February 13, 2007 |
PCT NO: |
PCT/JP2007/052453 |
371 Date: |
August 21, 2008 |
Current U.S.
Class: |
428/447 |
Current CPC
Class: |
C08L 83/08 20130101;
C09D 4/06 20130101; C09D 183/08 20130101; C08J 2367/02 20130101;
G02B 1/111 20130101; C08J 7/046 20200101; G02B 1/105 20130101; G02B
1/14 20150115; C08G 77/26 20130101; C08J 7/0427 20200101; C08J
7/043 20200101; G02B 1/16 20150115; C08J 7/044 20200101; Y10T
428/31663 20150401 |
Class at
Publication: |
428/447 |
International
Class: |
B32B 27/20 20060101
B32B027/20 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 22, 2006 |
JP |
2006-045163 |
Claims
1. An antistatic hard coat film comprising a base material and an
antistatic hard coat layer formed from an ionizing radiation
curable resin, a pigment and a polymer antistatic agent having an
organopolysiloxane unit and a quaternary ammonium salt unit and
provided on at least one surface of the base material, wherein
content of the pigment is 1 to 5% by weight of the total solid
content of the hard coat layer.
2. The antistatic hard coat film according to claim 1, wherein the
content of the pigment is 3% by weight or less of the total solid
content of the hard coat layer.
3. The antistatic hard coat film according to claim 1, wherein
weight ratio of the ionizing radiation curable resin and the
polymer antistatic agent is 8:2 to 4:6.
4. The antistatic hard coat film according to claim 3, wherein
weight ratio of the ionizing radiation curable resin and the
polymer antistatic agent is 6:4 to 5:5.
5. The antistatic hard coat film according to claim 4, wherein the
pigment consists of resin beads.
6. The antistatic hard coat film according to claim 3, wherein the
pigment consists of resin beads.
7. The antistatic hard coat film according to claim 2, wherein
weight ratio of the ionizing radiation curable resin and the
polymer antistatic agent is 8:2 to 4:6.
8. The antistatic hard coat film according to claim 7, wherein
weight ratio of the ionizing radiation curable resin and the
polymer antistatic agent is 6:4 to 5:5.
9. The antistatic hard coat film according to claim 8, wherein the
pigment consists of resin beads.
Description
TECHNICAL FIELD
[0001] The present invention relates to an antistatic hard coat
film which has antistatic property and antireflection property for
external lights as well as superior hard coat properties such as
superior surface hardness and antiscratching property.
BACKGROUND ART
[0002] It is known that a hard coat layer is formed as an outermost
surface layer on a base film as a general means for increasing
surface hardness of cover films such as protective films and
thereby improving antiscratching property thereof. It is prevalent
that a pigment is added to such a hard coat layer to prevent
reflection of lights of fluorescent lights and so forth.
[0003] However, since such a hard coat layer shows superior
insulating property, it has a problem that it is easily charged
with static electricity etc., and adhesion of dusts to product
surfaces consisting of such a hard coat layer degrades
visibility.
[0004] In order to solve such a problem, it is possible to provide
an antistatic layer or conductive layer in addition to the hard
coat layer. However, there may arise other problems such as
exfoliation of the layer because adhesion of such a layer to the
hard coat layer is bad. Therefore, it is prevalent that an
antistatic agent is added to the hard coat layer. As the antistatic
agent used for this purpose, low molecular antistatic agents and
metal fine particles are used (Patent document 1).
Patent document 1: Japanese Patent Unexamined Publication (KOKAI)
No. 2005-43647 (claims)
DISCLOSURE OF THE INVENTION
[0005] Object to be Achieved by the Invention
[0006] However, addition of a low molecular antistatic agent still
has a problem, that is, even if a low molecular antistatic agent is
added, it does not favorably exude on the hard coat layer surface,
and thus antistatic property cannot be obtained. Further, if metal
fine particles are added, there arises a problem that reflection of
outer lights cannot be prevented, even if a pigment is added.
[0007] Meanwhile, as polymer antistatic agents, those utilizing a
hydrophilic polymer as a base material and cationic polymer
compounds are known. When such polymer antistatic agents are used,
reflection of outer lights can be prevented by matting, and
antistatic property can also be attained. However, the leveling
property of the coated film becomes bad, and unevenness of the
coated film is generated. If a leveling agent usually used in such
a case is added, antistatic property can no longer be obtained,
although unevenness of the coated film can be eliminated.
[0008] The present invention was accomplished in view of the
aforementioned situation, and aims at providing an antistatic hard
coat film which shows antistatic property and antireflection
property for outer lights as well as superior hard coat properties
such as superior surface hardness and antiscratching property.
Means for Achieving the Object
[0009] The antistatic hard coat film of the present invention,
which achieves the aforementioned object, comprises a base material
and an antistatic hard coat layer formed from an ionizing radiation
curable resin, a pigment and a polymer antistatic agent having an
organopolysiloxane unit and a quaternary ammonium salt unit and
provided on at least one surface of the base material, wherein the
content of the pigment is 1 to 5% by weight of the total solid
content of the hard coat layer. The content of the pigment is
preferably 3% by weight or less.
[0010] Weight ratio of the ionizing radiation curable resin and the
polymer antistatic agent is preferably 6:4 to 5:5.
EFFECT OF THE INVENTION
[0011] According to the present invention, by using a polymer
antistatic agent having an organopolysiloxane unit and a quaternary
ammonium salt unit as an antistatic agent for the hard coat layer
containing an ionizing radiation curable resin, and adding a small
amount of a pigment to the hard coat layer, high antistatic
property and antireflection property for outer lights can be
obtained. There is thereby provided an antistatic hard coat film
showing favorable antistatic property, antireflection property for
outer lights and hard coat properties such as surface hardness and
antiscratching property.
BEST MODE FOR CARRYING OUT THE INVENTION
[0012] Hereafter, embodiments of the antistatic hard coat film of
the present invention will be explained.
[0013] The base material is not particularly limited, and various
polymer films and sheets, paper, glass and other molded products
formed from various materials can be suitably used. The base
material may be either transparent or opaque. However, when the
film is used as an optical member, optical characteristics thereof
such as transparency and refractive index should be taken into
consideration, and impact resistance, heat resistance, durability
and so forth are further taken into consideration. As such a base
material, those consisting of, for example, one or more kinds of
polyester type resins, acrylic type resins, acrylic urethane type
resins, polyester acrylate type resins, polyurethane acrylate type
resins, epoxy acrylate type resins, urethane type resins, epoxy
type resins, polycarbonate type resins, cellulose type resins,
acetal type resins, vinyl type resins, polyethylene type resins,
polystyrene type resins, polypropylene type resins, polyamide type
resins, polyimide type resins, melamine type resins, phenol type
resins, silicone type resins and fluorocarbon type resins can be
used. Although thickness of the base material is not particularly
limited so long as handling thereof is not obstructed, it is about
25 to 500 .mu.m, preferably 50 to 300 .mu.m.
[0014] The antistatic hard coat layer is formed on at least one
surface of the base material, and is formed from an ionizing
radiation curable resin, a pigment and a polymer antistatic agent
having an organopolysiloxane unit and a quaternary ammonium salt
unit.
[0015] As the ionizing radiation curable resin, photopolymerizable
prepolymers curable by crosslinking upon irradiation of ionizing
radiation (ultraviolet radiation or electron beam) can be used. As
such photopolymerizable prepolymers, acrylic type prepolymers which
have two or more acryloyl groups in one molecule and form a
three-dimensional reticular structure upon curing by crosslinking
are particularly preferably used. As the acrylic type prepolymers
include polyurethane acrylates, polyester acrylates, polyepoxy
acrylates, melamine acrylates, polyfluoroalkyl acrylates, silicone
acrylates and so forth can be used. Although these acrylic type
prepolymers can be used independently, they are preferably used as
a mixture with a photopolymerizable monomer in order to improve
crosslinking curable property and further improve hardness of the
surface protection film.
[0016] As the photopolymerizable monomer, one or more kinds of
monofunctional acrylic monomers such as 2-ethylhexyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and butoxyethyl
acrylate, bifunctional acrylic monomers such as 1,6-hexanediol
diacrylate, neopentylglycol diacrylate, diethylene glycol
diacrylate, polyethylene glycol diacrylate and hydroxypivalic acid
ester neopentylglycol diacrylate, polyfunctional acrylic monomers
such as dipentaerythritol hexaacrylate, trimethylpropane
triacrylate and pentaerythritol triacrylate, and so forth are
used.
[0017] When the antistatic hard coat layer is cured by ultraviolet
irradiation, it is preferable to use additives such as
photopolymerization initiators and photopolymerization enhancers,
besides the aforementioned photopolymerizable prepolymers and
photopolymerizable monomers.
[0018] Examples of the photopolymerization initiators include
acetophenone, benzophenone, Michler's ketone, benzoin, benzyl
methyl ketal, benzoyl benzoate, .alpha.-acyl oxime ester,
thioxanthones, and so forth.
[0019] The photopolymerization enhancers can accelerate the curing
rate by reducing polymerization disturbance caused by oxygen in the
air at the time of curing, and examples include
p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic
acid ethyl ester, and so forth.
[0020] As the ionizing radiation curable resin, besides the
aforementioned resins, resins having light stabilizing property
such as resins having ultraviolet absorbing property can be used.
Examples of the resin having ultraviolet absorbing property include
ultraviolet absorbing acrylic resins, and copolymers of
benzotriazole and (meth)acrylic acid ester are preferred. Moreover,
as the photopolymerizable monomer, polyfunctional acrylic monomers
showing ultraviolet absorbing property, such as monomers having a
bisbenzotriazolylphenol structure, may be used. By using such an
ionizing radiation curable resin having ultraviolet absorbing
property, degradation of the base material by ultraviolet radiation
can be prevented.
[0021] If the ionizing radiation curable resin is chosen so that it
should cure in a ultraviolet region (wavelength region) different
from the ultraviolet region (wavelength region) of which
ultraviolet rays are absorbed by the resin, the ionizing radiation
curable resin should have ultraviolet absorbing property.
[0022] Moreover, a light stabilizer, for example, hindered amine
type light stabilizers generically called HALS, or an ultraviolet
absorber can be added to the ionizing radiation curable resin. The
ultraviolet absorber is not particularly limited, and examples
include conventionally known ultraviolet absorbers such as
salicylic acid type compounds, cyanoacrylate type compounds,
benzophenone type compounds and benzotriazole type compounds, and
so forth. Among these, benzophenone type compounds and/or
benzotriazole type compounds are preferred in view of weather
resistance, for example, at the time of using the film in the
outdoors.
[0023] When an ionizing radiation curable resin having ultraviolet
absorbing property is used, and when an ultraviolet absorber is
used, the photopolymerization initiator for the ionizing radiation
curable resin mentioned above can be used. In such a case, it is
preferable to use a photopolymerization initiator showing an
absorption peak at a wavelength different from the ultraviolet
absorption peak of the ultraviolet absorber by 20 nm or more. The
surface protection layer can be thereby sufficiently cured, and
superior hard coat properties can be imparted.
[0024] As for the ultraviolet absorbing property of the surface
protection layer, it is sufficient that it can reduce light
transmission at a wavelength of 380 nm to about 40 to 70%. Although
the content of the ultraviolet absorber in the hard coat layer
changes depending on thickness of the layer, it may be not less
than about 0.5% by weight and not more than about 10% by weight,
preferably not less than about 1% by weight and not more than about
7% by weight, of the hard coat layer.
[0025] By choosing a content of the ultraviolet absorber in such a
range, degradation of the hard coat properties and degradation of
the hard coat layer and plastic film by ultraviolet radiation can
be prevented with a minimum content of the ultraviolet absorber in
the hard coat layer, and at the same time, stress of ultraviolet
radiation on the hard coat layer can be reduced to improve
durability of the ultraviolet shielding property of the hard coat
layer.
[0026] Since thickness of the hard coat layer may change depending
on the content of the light stabilizer and so forth, it cannot be
generally defined. However, when the hard coat properties are taken
into consideration, it is preferably about 1 to 15 .mu.m, more
preferably about 3 to 10 .mu.m. With a thickness of the hard coat
layer of 1 .mu.m or larger, sufficient hard coat properties and
required light stability such as ultraviolet shielding property can
be imparted. Further, with a thickness of 15 .mu.m or smaller,
generation of curl due to shrinkage of the hard coat layer upon
curing can be prevented, undercure of the layer can be prevented,
and exudation of the light stabilizers such as the ultraviolet
absorber can be prevented.
[0027] Examples of the pigment used for the present invention
include inorganic pigments such as silica, clay, talc, calcium
carbonate, calcium sulfate, barium sulfate, aluminum silicate,
titanium oxide, synthetic zeolite, alumina and smectite, and
organic pigments such as resin beads consisting of styrene resin,
urethane resin, benzoguanamine resin, silicone resin, acrylic resin
or the like, and hollow resin beads formed from them as raw
materials.
[0028] Addition amount of the pigment for preventing reflection of
outer lights is about 1 to 5% by weight, preferably about 1 to 3%
by weight, of the total solid content of the hard coat layer. With
a content of 1% by weight as the lower limit or larger, reflection
of outer lights can be prevented. With a content of 5% by weight as
the upper limit or smaller, degradation of surface hardness and
antiscratching property of the hard coat layer can be prevented. By
using the ionizing radiation curable resin and the polymer
antistatic agent having an organopolysiloxane unit and a quaternary
ammonium salt unit in combination, reflection of outer lights can
be prevented even with a smaller amount of the pigment compared
with the case where the ionizing radiation curable resin is used
alone.
[0029] The polymer antistatic agent imparts antistatic property to
the hard coat layer, and it is a polymer having an
organopolysiloxane unit and a quaternary ammonium salt unit, and
may have polymerizable functional groups such as (meth)acryloyl
group on side chains as required. Since the antistatic agent having
polymerizable functional groups chemically bonds to the ionizing
radiation curable resin as a component of the hard coat layer upon
ultraviolet radiation or electron beam irradiation, it can be fixed
in the hard coat layer not to exude from the hard coat layer and
thereby defluxion of the antistatic agent due to washing with
water, wiping or the like can be reduced.
[0030] Since the polymer antistatic agent can dispose the groups
imparting antistatic property on the hard coat layer surface by the
organopolysiloxane structure in the molecule, it can provide more
sufficient antistatic property even in the same amount as those of
conventional low molecular antistatic agents, without degrading the
hard coat properties such as surface hardness or antiscratching
property.
[0031] On the other hand, only with a polymer antistatic agent
having only a quaternary ammonium salt unit, leveling property is
degraded, although antistatic property can be obtained. If a
leveling agent is added, the leveling agent covers the hard coat
layer surface, and prevent the quaternary ammonium salt from
emerging on the surface, and therefore antistatic property can no
longer be obtained. In contrast, if a polymer having both an
organopolysiloxane unit and a quaternary ammonium salt unit is used
as in the present invention, the organopolysiloxane structure has
leveling property, therefore quaternary ammonium salts can be
disposed on the hard coat layer surface without requiring use of
another leveling agent, and therefore leveling property and
antistatic property can be imparted to the hard coat layer.
[0032] As the polymer antistatic agent having both an
organopolysiloxane unit and a quaternary ammonium salt unit, for
example, those described in Patent documents 2 and 3 can be
used.
Patent document 2: Japanese Patent Unexamined Publication No.
10-279833 Patent document 3: Japanese Patent Unexamined Publication
No. 2000-80169
[0033] Weight ratio of the ionizing radiation curable resin and the
polymer antistatic agent is determined in consideration of the
content of the quaternary ammonium salt unit contained in the
polymer antistatic agent. For example, content of quaternary
ammonium salt units contained in the available polymer antistatic
agents is less than 40% by weight, and in the case of these polymer
antistatic agents, the weight ratio of the ionizing radiation
curable resin and the polymer antistatic agent is 8:2 to 4:6,
preferably 7:3 to 5:5, more preferably 6:4 to 5:5. It is not
preferred that the polymer antistatic agent is contained in a large
amount, since quaternary ammonium salts are highly hygroscopic,
therefore the hard coat layer becomes cloudy uneven coated film due
to humidity, and thus appearance thereof is degraded. Moreover,
with only the polymer antistatic agent, hard coat properties become
insufficient. On the other hand, if amount of the ionizing
radiation curable resin increases, the leveling property of the
coated film is degraded, and optical characteristics become uneven.
As for surface hardness, hardness of at least about 2 to 3H is
practically sufficient.
[0034] The hard coat layer may contain various additives, such as
lubricants, fluorescent whitening agents, dyes, flame retardants,
antibacterial agents, antifungal agents, antioxidants,
plasticizers, leveling agents, flow regulators, antifoams,
dispersing agents and crosslinking agents, to such an extent that
the effect of the present invention should not be degraded.
[0035] The antistatic hard coat layer can be formed by mixing the
ionizing radiation curable resin, the pigment and the polymer
antistatic agent, as well as other resin, additive and dilution
solvent added as required to prepare a coating solution, applying
the solution by a conventionally known method such as bar coating,
die coating, blade coating, spin coating, roll coating, gravure
coating, curtain flow coating, spray coating and screen printing,
drying the coated layer, and optionally curing the layer by
irradiating the layer with ionizing radiation as required.
[0036] As for the method for irradiating ionizing radiation, the
irradiation can be attained by irradiating a ultraviolet ray in a
wavelength region of 100 to 400 nm, preferably 200 to 400 nm,
emitted from an ultra high pressure mercury lamp, a high pressure
mercury lamp, a low pressure mercury lamp, carbon arc, a metal
halide lamp, or the like, or by irradiating an electron beam in a
wavelength region of 100 nm or smaller emitted from a scanning type
or curtain type electron beam accelerator.
[0037] Moreover, in order to improve adhesion between the hard coat
layer and the base material, the base material may be optionally
subjected to an easy adhesion treatment.
[0038] The antistatic hard coat film of the present invention can
be used for uses in surface protection of liquid crystal displays,
plasma displays and rear projection displays, surface protection of
touch panels, and so forth.
EXAMPLES
[0039] Hereafter, the present invention will be further explained
with reference to examples. The term and symbol "part" and "%" are
used on weight basis, unless specifically indicated.
Example 1
[0040] On a base material consisting of a polyester film having a
thickness of 188 .mu.m (Lumirror U34, Toray Industries, Inc.), a
coating solution for hard coat layer having the following
composition was applied by bar coating so as to obtain a dry
thickness of 5 .mu.m, dried at 70.degree. C. for 2 minutes and
cured by ultraviolet irradiation from a high pressure mercury lamp
to form a hard coat layer and thereby prepare an antistatic hard
coat film of the present invention.
TABLE-US-00001 <Coating solution for hard coat layer>
Ultraviolet absorbing ionizing radiation 34 parts curable resin
(Aurex 359, solid content: 70% Chugoku Marine Paints, Ltd.) Polymer
antistatic agent having 32 parts organopolysiloxane unit and
quaternary ammonium salt unit (Yupimer UV H6100, solid content:
50%, Mitsubishi Chemical Corporation) Acrylic resin beads (MX500KS,
mean particle 0.7 part diameter: 5 .mu.m, Soken Chemical &
Engineering Co., Ltd.) Methyl ethyl ketone 34 parts Toluene 34
parts
Example 2
[0041] An antistatic hard coat film of Example 2 was prepared in
the same manner as that of Example 1 except that a coating solution
for hard coat layer having the following composition was used
instead of the coating solution for hard coat layer of Example
1.
TABLE-US-00002 <Coating solution for hard coat layer>
Ionizing radiation curable resin 30 parts (ACRYDIC 17-806, solid
content: 80% Dainippon Ink &Chemicals, Inc.) Polymer antistatic
agent having 32 parts organopolysiloxane unit and quaternary
ammonium salt unit (Yupimer UV H6100, solid content: 50%,
Mitsubishi Chemical Corporation) Acrylic resin beads (MX500KS, mean
particle 0.7 part diameter: 5 .mu.m, Soken Chemical &
Engineering Co., Ltd.) Methyl ethyl ketone 36 parts Toluene 36
parts
Example 3
[0042] An antistatic hard coat film of Example 3 was prepared in
the same manner as that of Example 1 except that a coating solution
for hard coat layer having the following composition was used
instead of the coating solution for hard coat layer of Example
1.
TABLE-US-00003 <Coating solution for hard coat layer>
Ionizing radiation curable resin 25 parts (ACRYDIC 17-806, solid
content: 80% Dainippon Ink &Chemicals, Inc.) Polymer antistatic
agent having 40 parts organopolysiloxane unit and quaternary
ammonium salt unit (Yupimer UV H6100, solid content: 50%,
Mitsubishi Chemical Corporation) Acrylic resin beads (MX500KS, mean
particle 0.7 part diameter: 5 .mu.m, Soken Chemical &
Engineering Co., Ltd.) Methyl ethyl ketone 33 parts Toluene 33
parts
Example 4
[0043] An antistatic hard coat film of Example 4 was prepared in
the same manner as that of Example 1 except that a coating solution
for hard coat layer having the following composition was used
instead of the coating solution for hard coat layer of Example
1.
TABLE-US-00004 <Coating solution for hard coat layer>
Ionizing radiation curable resin 20 parts (ACRYDIC 17-806, solid
content: 80% Dainippon Ink &Chemicals, Inc.) Polymer antistatic
agent having 48 parts organopolysiloxane unit and quaternary
ammonium salt unit (Yupimer UV H6100, solid content: 50%,
Mitsubishi Chemical Corporation) Acrylic resin beads (MX500KS, mean
particle 0.7 part diameter: 5 .mu.m, Soken Chemical &
Engineering Co., Ltd.) Methyl ethyl ketone 34 parts Toluene 34
parts
Example 5
[0044] An antistatic hard coat film of Example 5 was prepared in
the same manner as that of Example 1 except that a coating solution
for hard coat layer having the following composition was used
instead of the coating solution for hard coat layer of Example
1.
TABLE-US-00005 <Coating solution for hard coat layer>
Ionizing radiation curable resin 40 parts (ACRYDIC 17-806, solid
content: 80% Dainippon Ink &Chemicals, Inc.) Polymer antistatic
agent having 16 parts organopolysiloxane unit and quaternary
ammonium salt unit (Yupimer UV H6100, solid content: 50%,
Mitsubishi Chemical Corporation) Acrylic resin beads (MX500KS, mean
particle 0.7 part diameter: 5 .mu.m, Soken Chemical &
Engineering Co., Ltd.) Methyl ethyl ketone 37 parts Toluene 37
parts
Example 6
[0045] An antistatic hard coat film of Example 6 was prepared in
the same manner as that of Example 1 except that a coating solution
for hard coat layer having the following composition was used
instead of the coating solution for hard coat layer of Example
1.
TABLE-US-00006 <Coating solution for hard coat layer>
Ionizing radiation curable resin 25 parts (ACRYDIC 17-806, solid
content: 80% Dainippon Ink &Chemicals, Inc.) Polymer antistatic
agent having 40 parts organopolysiloxane unit and quaternary
ammonium salt unit (Yupimer UV H6100, solid content: 50%,
Mitsubishi Chemical Corporation) Acrylic resin beads (MX500KS, mean
particle 2.4 part diameter: 5 .mu.m, Soken Chemical &
Engineering Co., Ltd.) Methyl ethyl ketone 34 parts Toluene 34
parts
Comparative Example 1
[0046] An antistatic hard coat film of Comparative Example 1 was
prepared in the same manner as that of Example 1 except that a
coating solution for hard coat layer having the following
composition was used instead of the coating solution for hard coat
layer of Example 1.
TABLE-US-00007 <Coating solution for hard coat layer>
Ionizing radiation curable resin 50 parts (ACRYDIC 17-806, solid
content: 80% Dainippon Ink &Chemicals, Inc.) Acrylic resin
beads (MX500KS, mean particle 0.7 part diameter: 5 .mu.m, Soken
Chemical & Engineering Co., Ltd.) Methyl ethyl ketone 40 parts
Toluene 40 parts
Comparative Example 2
[0047] An antistatic hard coat film of Comparative Example 2 was
prepared in the same manner as that of Example 1 except that a
coating solution for hard coat layer having the following
composition was used instead of the coating solution for hard coat
layer of Example 1.
TABLE-US-00008 <Coating solution for hard coat layer>
Ionizing radiation curable resin 50 parts (ACRYDIC 17-806, solid
content: 80% Dainippon Ink &Chemicals, Inc.) Metal antistatic
agent 100 parts (Seikabeam HC15, solid content: 30%, Dainichiseika
Color &Chemicals Mfg. Co., Ltd.) Acrylic resin beads (MX500KS,
mean particle 0.7 part diameter: 5 .mu.m, Soken Chemical &
Engineering Co., Ltd.) Methyl ethyl ketone 40 parts Toluene 40
parts
Comparative Example 3
[0048] An antistatic hard coat film of Comparative Example 3 was
prepared in the same manner as that of Example 1 except that a
coating solution for hard coat layer having the following
composition was used instead of the coating solution for hard coat
layer of Example 1.
TABLE-US-00009 <Coating solution for hard coat layer>
Ionizing radiation curable resin 25 parts (ACRYDIC 17-806, solid
content: 80% Dainippon Ink &Chemicals, Inc.) Polymer antistatic
agent not having 100 parts organopolysiloxane unit and quaternary
ammonium salt unit (Seikabeam EPF-EPR2, solid content: 20%,
Dainichiseika Color & Chemicals Mfg. Co., Ltd.) Acrylic resin
beads (MX500KS, mean particle 0.7 part diameter: 5 .mu.m, Soken
Chemical & Engineering Co., Ltd.) Leveling agent 0.5 part
(Paintad M, Dow Corning Co., Ltd.) Methyl ethyl ketone 5 parts
Toluene 5 parts
Comparative Example 4
[0049] An antistatic hard coat film of Comparative Example 4 was
prepared in the same manner as that of Example 1 except that a
coating solution for hard coat layer having the following
composition was used instead of the coating solution for hard coat
layer of Example 1.
TABLE-US-00010 <Coating solution for hard coat layer> Polymer
antistatic agent having 80 parts organopolysiloxane unit and
quaternary ammonium salt unit (Yupimer UV H6100, solid content:
50%, Mitsubishi Chemical Corporation) Acrylic resin beads (MX500KS,
mean particle 0.7 part diameter: 5 .mu.m, Soken Chemical &
Engineering Co., Ltd.) Methyl ethyl ketone 25 parts Toluene 25
parts
[0050] The hard coat films of Examples 1 to 6 and Comparative
Examples 1 to 4 were evaluated for the following items. The results
are shown in Table 1.
<Antistatic Property>
[0051] Surface resistance (.OMEGA./.quadrature.) was measured for
hard coat layer surface of each hard coat film in an environment of
a temperature of 20.degree. C. and a humidity of 60% RH with a high
resistance meter (3329A, Hewlett Packard Co.). The results lower
than 1.0.times.10.sup.11.OMEGA./.quadrature. are indicated with the
symbol ".smallcircle.", and the results not lower than
1.0.times.10.sup.11.OMEGA./.quadrature. are indicated with the
symbol "x".
<Antireflection Property>
[0052] Each hard coat film was laminated on a CRT screen displaying
images. When the images became invisible due to reflection of outer
lights, the result is indicated with the symbol x, when the images
became hard to see, the result is indicated with the symbol
".DELTA.", and when images did not become hard to see, the result
is indicated with the symbol ".smallcircle.".
<Whitening>
[0053] Each hard coat film was superimposed on a black sheet. When
white unevenness of the coated film was observed in the hard coat
film by visual inspection, the result is indicated with the symbol
"x", and when such unevenness was not observed, the result is
indicated with the symbol ".smallcircle.".
<Surface Hardness>
[0054] Pencil hardness of each hard coat film was measured for the
hard coat layer side according to the pencil scratch test machine
method defined in JIS-K 5400:1990. Evaluation was performed on the
basis of scratch of the coated film. As for the results, pencil
hardness not lower than 2H is indicated with the symbol
".smallcircle.", pencil hardness of from B to 2B is indicated with
the symbol ".DELTA.", and pencil hardness not higher than 4B is
indicated with the symbol "x".
<Antiscratching Property>
[0055] For each of the hard coat films of the examples and
comparative examples, the surface was reciprocally rubbed times
with steel wool of #0000 under a load of 0.98 N/cm.sup.2. When no
scratch was seen on the surface, the result is indicated with the
symbol ".smallcircle.", when there were certain scratches, the
result is indicated with the symbol ".DELTA.", and when there were
scratches, the result is indicated with the symbol "x".
<Appearance>
[0056] Each hard coat film was evaluated by visual inspection with
transmitting light. When uneven light transmission was observed due
to unevenness of the hard coat layer surface of the hard coat film
or uneven coating, the result is indicated with the symbol "x",
when slight unevenness was observed, the result is indicated with
the symbol ".DELTA.", and when unevenness was not observed, the
result is indicated with the symbol ".smallcircle.".
TABLE-US-00011 TABLE 1 Anti- Anti- Antistatic reflection Surface
scratching property property Whitening hardness property Appearance
Example 1 .smallcircle. .smallcircle. .smallcircle. .smallcircle.
.smallcircle. .smallcircle. Example 2 .smallcircle. .smallcircle.
.smallcircle. .smallcircle. .smallcircle. .smallcircle. Example 3
.smallcircle. .smallcircle. .smallcircle. .smallcircle.
.smallcircle. .smallcircle. Example 4 .smallcircle. .smallcircle.
.smallcircle. .DELTA. .DELTA. .smallcircle. Example 5 .smallcircle.
.smallcircle. .smallcircle. .smallcircle. .smallcircle. .DELTA.
Example 6 .smallcircle. .smallcircle. .smallcircle. .DELTA. .DELTA.
.smallcircle. Comparative x .DELTA. .smallcircle. .smallcircle.
.smallcircle. x Example 1 Comparative .smallcircle. x .smallcircle.
.smallcircle. .smallcircle. .DELTA. Example 2 Comparative x .DELTA.
.smallcircle. .smallcircle. .smallcircle. .smallcircle. Example 3
Comparative .smallcircle. .smallcircle. x x x .smallcircle. Example
4
[0057] The antistatic hard coat films of Examples 1 to 3 had an
antistatic hard coat layer containing a polymer antistatic agent
having an organopolysiloxane unit and a quaternary ammonium salt
unit on a base material. Therefore, the antistatic hard coat films
of Examples 1 to showed superior results in evaluation for all of
antistatic property, antireflection property, whitening, surface
hardness and antiscratching property. Moreover, since the
antistatic hard coat film of Example 1 contained a resin having
ultraviolet absorbing property as the ionizing radiation curable
resin, the film showed superior light resistance.
[0058] The antistatic hard coat film of Example 4 also had an
antistatic hard coat layer containing a polymer antistatic agent
having an organopolysiloxane unit and a quaternary ammonium salt
unit on a base material. However, since the hard coat film of
Example 4 contained a large amount of the polymer antistatic agent
having an organopolysiloxane unit and a quaternary ammonium salt
unit, it showed surface hardness and antiscratching property
inferior to those of the antistatic hard coat films of Examples 1
to 3. It showed superior results for antistatic property,
antireflection property and whitening.
[0059] The antistatic hard coat film of Example 5 contained only a
small amount of the antistatic agent (20% by weight). Although it
showed results equivalent to those of the antistatic hard coat
films of Examples 1 to 3 for the evaluation items except for
appearance, it showed appearance inferior to that of the films of
the other examples, since the leveling effect of the
organopolysiloxane was insufficient, and thus unevenness was
generated in the coated film.
[0060] The antistatic hard coat film of Example 6 contained the
pigment at a content of 6% by weight, i.e., contained more pigment
than the films of the other examples. Therefore, it showed surface
hardness and antiscratching property inferior to those of the films
of the other examples. Moreover, although unevenness was not
observed concerning appearance, haze was also slightly high due to
the addition of the pigment. It showed evaluation results
equivalent to those of the films of Examples 1 to 3 for the items
other than surface hardness and antiscratching property.
[0061] The hard coat film of Comparative Example 1 did not
contained the antistatic agent in the hard coat layer. Therefore,
the hard coat film of Comparative Example 1 showed inferior
antistatic property. Moreover, since it did not utilize the polymer
antistatic agent having an organopolysiloxane unit and a quaternary
ammonium salt unit, antireflection effect could be obtained only by
addition of the pigment, and it showed slightly inferior
antireflection property.
[0062] The hard coat film of Comparative Example 2 contained a
metal antistatic agent in the hard coat layer. Therefore, the hard
coat film of Comparative Example 2 showed inferior antireflection
property, even though it contained a pigment.
[0063] The hard coat film of Comparative Example 3 contained the
polymer antistatic agent and a leveling agent in the hard coat
layer. Therefore, since the leveling agent inhibited disposition of
the antistatic agent on the hard coat layer surface, the hard coat
film of Comparative Example 3 showed inferior antistatic property.
Moreover, since it contained a polymer antistatic agent not having
organopolysiloxane unit and quaternary ammonium salt unit,
antireflection effect could be obtained only by addition of the
pigment, and it showed slightly inferior antireflection
property.
[0064] The hard coat film of Comparative Example 4 contained only
the polymer antistatic agent having an organopolysiloxane unit and
a quaternary ammonium salt unit in the hard coat layer. Therefore,
the hard coat film of Comparative Example 4 showed inferior surface
hardness. Furthermore, since it contained a large amount of the
quaternary ammonium salt, it showed generation of white unevenness,
which was not generated in the hard coat layers of Examples 1 to 4
containing the same polymer antistatic agent as that of Comparative
Example 4.
* * * * *